TreeIterCompareFunc


Description:

public delegate int TreeIterCompareFunc (TreeModel model, TreeIter a, TreeIter b)

A GtkTreeIterCompareFunc should return a negative integer, zero, or a positive integer if a sorts before b, a sorts with b, or a sorts after b respectively.

If two iters compare as equal, their order in the sorted model is undefined. In order to ensure that the TreeSortable behaves as expected, the GtkTreeIterCompareFunc must define a partial order on the model, i.e. it must be reflexive, antisymmetric and transitive.

For example, if model is a product catalogue, then a compare function for the “price” column could be one which returns `price_of(a) - price_of(b)`.

Parameters:

model

The TreeModel the comparison is within

a

A TreeIter in model

b

Another TreeIter in model

user_data

Data passed when the compare func is assigned e.g. by set_sort_func

Returns:

a negative integer, zero or a positive integer depending on whether a sorts before, with or after b


Namespace: Gtk
Package: gtk+-3.0